The present invention relates generally to pellet fuel heating units or burners, and more particularly to a grill that utilizes a solid pellet type fuel, and particularly corn kernels.
The use of solid pellets as a fuel source is known, particularly in the art of stoves and the like. For example, U.S. Pat. No. 5,351,633 describes a heating unit particularly suited for burning corn kernels. The corn kernels provide an inexpensive, clean, and readily available fuel source. Other types of solid pellet heating units are also available, for example wood pellet heating units are also known.
A substantial problem with conventional fuel heating units has been the ability to consistently sustain the combustion reaction. One typical problem is with the method of providing air to the fuel to sustain the combustion. Typical stoves or heating units are closed and vented systems and utilize either a positive or negative pressure system for supplying combustion air to the heating unit. The conventional systems utilize a blower to supply air to the burner portion of the heating unit. If the blower is located upstream of the heating unit, than the unit is said to be a positive pressure system since the fire box will have a pressure greater than atmospheric. If the blower is located beyond or downstream of the fuel burner, the system is a negative pressure system and combustion air is essentially sucked into the burner, which has a pressure slightly less than atmospheric.
However, the use of either positive or negative pressure systems present several problems. For example, with the positive pressure system, the fire box is under pressure so that when the door or other access to the fire box is opened, smoke and other matter is generally pushed into the room. With the negative pressure system, there is a tendency for the blower to clog from the particulate material and the exhaust gases. Neither of these systems would be particularly suitable for outdoor grill applications.
The use of charcoal, gas, and wood as a fuel source for outdoor barbeque grills is well known. The styles and configurations of outdoor grills are vast and varied in the industry. However, conventional grills have inherent disadvantages depending particularly on the type of fuel utilized by the grill. For example, creosote chemicals, hydrocarbons, gases, and other undesirable chemicals actually cook into the food, particularly if charcoal or wood is the fuel source.
Propane or natural gas grills pose the additional disadvantages of potential dangerous leaks, and explosion hazzards.
Accordingly, the industry is continuously seeking to improve the safety, economy, and overall reliability and effectiveness of outdoor grills.
The present invention seeks to provide an improved solid pellet heating unit that is particularly suited for, but not limited to, an outdoor grill while overcoming the problems encountered with conventional solid pellet fuel burning units.